I assume you are using OpenGL? I have some problems with the performance of the emulator using OpenGL, that will become an issue for me later. As far as I can tell the biggest problem is texture mapping - two triangles with a texture that fills the whole screen (a background) is enough to make the emulator slow (5-10 fps). For now I have "solved" the problem by having alternate, simplified draw modes for my objects while I am running in the emulator.
I expect the G1 and other hardware devices to perform well in OpenGL - it is probably just an issue with the emulation. I would really love to hear if anyone has been able to get good performance using texture-mapping in the emulator.